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Anvesh Annadanam, Varshini Varadaraj, Lucy Mudie, Alice Liu, William G. Plum, Kevin White, Megan E Collins, David S Friedman; Self-refraction using a simple device reliably predicts manifest refraction. Invest. Ophthalmol. Vis. Sci. 2017;58(8):2394. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
Uncorrected refractive error (RE) is the most common cause of preventable visual impairment globally. The need for highly trained personnel to carry out refractions increases the cost of spectacles and limits outreach in poorer regions. Newer technologies allowing for self-refraction (SR) may be a cost-effective alternative. The USee device contains a self-adjustable refraction bar that allows users to determine their own spherical RE. We report on the accuracy and usability of the USee compared to conventional methods in measuring RE.
A total of 60 adults with uncorrected visual acuity (VA) worse than 20/30 in either eye and spherical equivalent (SE) RE between –6.00 and +6.00 diopters (D) completed clinical manifest refraction (MR) by an optometrist, self-refraction (SR) with the USee, autorefraction with a tabletop or handheld device, and VA testing using a computerized logMAR chart.
Subjects were a mean (±SD) 53.1 (±18.6) years of age, and 27 (45.0%) were male. More than half (61.7%) presented with glasses. The mean (±SD) SE for right eyes measured by MR [–0.90 D (±2.53)] differed significantly from that measured by SR [–1.22 D (±2.42)], p < 0.002]. The proportion of subjects correctable to 20/30 or better in the better eye was higher for MR (96.7%) than SR (83.3%, p < 0.006). In right eyes, SE measured by SR differed from MR by < 1.00 D in either direction in 81.7% of participants (Figure 1). In logistic regression models, failure to achieve VA ≥ 20/30 in the right eye with SR was associated with increasing age (per year, OR: 1.05; 95% CI: 1.00 to 1.10; p = 0.017) and higher cylindrical power (per D, OR: 7.26; 95% CI: 1.88 to 28.1; p = 0.004). In terms of subjective feedback, 95% thought the USee was easy to use, 85% thought the SR correction was better than being uncorrected, 57% thought the SR correction was as good as their current corrective lenses, and 53% rated their vision as “very good” or “excellent” with SR correction.
The USee provides acceptable RE and VA correction in adults. Older age and higher cylindrical power were associated with poorer VA outcomes. Although the device cannot correct astigmatism, many subjects found it easy to use and better than wearing no corrective lenses. Programs using the USee system could provide glasses on the spot and satisfaction could be determined immediately with pop-in glasses.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
Difference between MR and SR vs. MR
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